Many fans haven't gotten over Kirk's death in Generations. You think they're going to stand for him to be killed before TOS even happens?
As for Pike: This is what we signed up for when they said "Hey, let's make a show about Pike!" If anything they've managed to weave in his eventual accident as part of the fabric of the show rather than coming out of nowhere. (As, you know, tragic accidents do.)
One might wonder (assuming she's still around) why Una never found Kirk and Spock (Spock doesn't know, does he?) after The Menagerie and said "Yeah. He knew this was coming. He was OK with it."
I don't think they'll wrap up the show by subverting the accident as much as possibly wrapping things up afterwards.
Heck, maybe they'll do a version of The Menagerie where we get all cards on the table with knowing that Uhura, Chapel, and Scotty all had served with Pike and seeing their reactions to the accident and Spock's mutiny. Just a) do a better job than A Quality of Mercy and b) don't screw up the TMP uniforms like they screwed up the TWOK uniforms. (And if you want to fix the SNW TWOK uniforms that would be swell. Thanks.)